The invention relates to an arrangement for the intermediate storage of a double yarn formed of two yarn components which is arranged between a delivery device and a yarn connecting device and which, during the establishing of a connection between the double yarn delivered by the delivery device and a yarn taken from a wind-up spool, receives the continuously delivered yarn length in a suction chamber.
In a known arrangement of the initially mentioned type (DE-A 36 11 505), a suction chamber is provided which receives, in the shape of a loop, the double yarn delivered continuously during the establishing of a yarn connection. It was found that at very high delivery speeds, a relatively large yarn length must be stored intermediately which requires a very long suction chamber for which the available space is frequently not sufficient.
In commonly assigned U.S. patent application Ser. No. 350,520, filed May 11, 1989, now U.S. Pat. No. 4,958,486, Sep. 25, 1990 corresponding to German Patent Application (P 38 17 222.4), which is not a prior publication, an arrangement is disclosed for the intermediate storage in which the the suction chamber has an air permeable depositing surface for the double yarn so that this double yarn can be deposited in loop shapes on top of one another, which may be called a "semirandom" storage.
During the intermediate storing of double yarns, particularly of double yarns which are formed of two essentially untwisted yarn components which are only prestrengthened by means of pneumatic false-twist spinning, there is the additional risk that disturbances occur as a result of the fact that the two yarn components shift with respect to one another so that undesirable yarn loops are formed in the individual yarn components. There is the danger that yarn loops of this type do not open up completely when the double yarn is withdrawn from the intermediate storage device so that disturbances may occur.
The invention is based on the object of providing an arrangement of the initially mentioned type in which, on the one hand, a relatively large length of a double yarn can be stored intermediately and in which, on the other hand, it is securely prevented that the yarn components of the double yarn shift with respect to one another.
This object is achieved in that the suction chamber has an air permeable depositing surface for the double yarn and that, at the inlet side of the suction chamber, an air nozzle is provided which receives the double yarn and delivers it to the suction chamber.
In the suction chamber, the double yarn is "semirandomly" deposited in the form of loops. The air nozzle located at the inlet side has the effect that a certain connection is generated between the two yarn components because individual fiber ends projecting from the yarn components intermingle or hook into one another which significantly reduces the risk that the two yarn components shift with respect to one another inside the suction chamber.
In a further development of the invention, it is provided that the air nozzle, at the edge of the suction chamber, is arranged at a point which is opposite the Point of the edge which serves as a deflection for the running-off double yarn. As a result, the entering double yarn is largely separated from the emerging double yarn so that favorable conditions exist particularly for the emptying of the suction chamber.
In a further development of the invention, it is provided that the depositing surface is arranged diagonally with respect to the longitudinally extending axis of the suction chamber. In this case, it is advantageous for the depositing surface to have a larger distance to the air nozzle than to the deflection for the running-off double yarn. In this manner, the loops are deposited diagonally with respect to the withdrawal direction so that the emerging double yarn can be pulled out more easily from under the deposited loops.
In a further development of the invention, it is provided that the air nozzle is constructed as a twisting nozzle which is provided with a longitudinal slot. This twisting nozzle provides the double yarn with a false twist which opens up again when it emerges from the twisting nozzle. During this opening-up of the false twist, several fiber ends remain wound around both yarn components so that the two yarn components are at least somewhat connected with one another.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.